The purpose of this contract is to discover and to begin to characterize novel human genes expressed preferentially in embryonic rhombomeres and first branchial arch, oral cavity (including teeth, salivary glands and tongue), and maxilla. It will provide a national resource of novel data and human DNA clones relevant to oral and craniofacial genetics and development. The specific goals are: 1. Produce a set of accurately staged tissue-specific and developmental stage-specific human craniofacial cDNA libraries, with documentation concerning the tissue (source and quality), embryonic stage, and quality of the library. 2. The standard, normalized, subtracted, and SAGE libraries shall be deposited in a public repository such as managed by the ATCC or I.M.A.G.E. consortium, or they can alternatively be provided to the NIDCR Project Officers. In addition, cDNA libraries covering many of the early stages of human oral and craniofacial development shall be provided to the I.M.A.G.E. consortium for conventional EST generation. 3. Apply screening approaches to compare the genes expressed in the different human craniofacial embryonic stages or tissues, in order to generate information that researchers in the field can use to obtain and characterize cDNA clones that are developmental stage-specific and tissue-specific. 4. Identify and isolate stage-specific (particularly from early stages) or unusually highly expressed tissue-specific clones. 5. Information generated by this contract, including DNA sequences and summaries of database searches, shall be made publicly available promptly. There should be open release of data as it becomes available by deposit in a web site.